This invention relates to irradiation systems which utilize a conveyor system for transporting articles in a chamber through a target region scanned by radiation from a radiation source. The invention is particularly related (1) to a system for synchronizing the movements of queues providing for the movements of the articles into the chamber, past the radiation source for irradiation of the articles and then from the chamber after the irradiation of the articles and (2) to the disposition of a shield in the chamber for inhibiting radiation from reaching the queues and the walls of the invention.
Co-pending application Ser. No. 09/102,942 by John Thomas Allen et al. on Jun. 23, 1998, and assigned of record to the assignee of record of this application discloses and claims an article irradiation system which includes (1) a radiation source for scanning a target region with radiation, (2) a conveyor system including a process conveyor positioned for transporting articles in a given direction through the target region and (3) radiation shielding material defining the walls of a chamber containing the radiation source, the target region and a portion of the conveyor system. The radiation source is disposed inside a loop defined by a portion of the conveyor system and is adapted to scan the articles in the chamber in a plane transverse to the given direction of transport by the process conveyor. A shield (e.g., an intermediate wall) of radiation shielding materials positioned within the loop supports a radiation shielding ceiling of the chamber, inhibits photons emitted from a beam stop in one of the chamber walls from impinging on other walls of the chamber and restricts flow in the chamber of ozone derived in the target region from the radiation source.